It is known to react 1-cyclohexene-1,2-dicarboxylic anhydride (1-CDA) thermally with conjugated dienes such as butadiene (Ber. 71B, 2199, 2280 (1938)), dimethylbutadiene and isoprene (J. Org. Chem., 23, 485 (1958)) under vigorous conditions. 1-CDA fails to react with furan, chloroprene, or cyclopentadiene at high temperatures (J. Org. Chem., 23, 485 (1958)). The imides of 1-CDA, shown to be herbicidal, as taught in U.S. Pat. No. 4,032,326, are prepared by heating the anhydride with diamines. U.S. Pat. No. 4,225,505 teaches that pyrolysis of some 1-CDA imides under extreme conditions gives pyromellitimides. It has been reported (Angew. Chem. Int. Ed. Engl., 17, 758, (1978)) that photochemical irradiation of 1-CDA in the presence of trans-stilbene gave spirooxetanes and not a 2+2 cycloadduct.
Novel dianhydrides prepared by photoaddition reactions of 1-CDA or dimethylmaleic anhydride and polyimides based upon these monomers are described by T. S. Nimry et al. in commonly assigned U.S. Ser. Nos. 294,332; 294,345; 294,347; and 294,348, filed Aug. 14, 1981, the disclosures of which are hereby incorporated by reference. In general, the photoadducts are made by irradiating the above monomers in the presence of other cyclic anhydrides and small quantities of benzophenone as sensitizer. The 1-CDA monomer is prepared by isomerization of cis-4-cyclohexene-1,2-dicarboxylic anhydride, the Diels-Alder adduct of butadiene and maleic anhydride, by heating with a few weight percent of phosphorus pentoxide (P.sub.2 O.sub.5) at 200.degree. C. (M. E. Bailey and E. O. Amstrutz, J. Am. Chem. Soc., 78, 3828 (1956)).
In reviewing these references, it is clear that irradiation of 1-CDA in the presence of olefinic and allyl compounds to form cycloadducts has not been contemplated. Neither has the art contemplated the novel bicyclooctanes prepared as photoadducts of 1-cyclohexene-1,2-dicarboxylic anhydride (1-CDA) and olefins.
The general object of this invention is to provide novel bicyclooctane compositions based upon 1-CDA and one or more olefin moieties. A more specific object of this invention is to provide photoadducts of 1-CDA and aliphatic olefins from 2-30 carbon atoms and cycloaliphatic olefins from 5-30 carbon atoms containing substituents such as halogen, cyano, nitro and alkoxy groups. Another object is to provide derivatives of the novel bicyclooctane compositions prepared by esterification and reaction with amines to form amine salts.